Adherent device for respiratory monitoring

ABSTRACT

A respiratory monitoring system is provided. A measuring system is provided that includes, (i) an adherent device configured to be coupled to a patient, the adherent device including a plurality of sensors that monitor respiratory status, at least one of the sensors configured to monitor the patient&#39;s respiration, and (ii) a wireless communication device coupled to the plurality of sensors and configured to transfer patient data directly or indirectly from the plurality of sensors to a remote monitoring system. A remote monitoring system is coupled to the wireless communication device.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application claims the benefit under 35 USC 119(e) of U.S.Provisional Application No. 60/972,363, 60/972,537, 60/972,336 all filedSep. 14, 2007; and 61/055,656 and 61/055,666 both filed May 23, 2008;the full disclosures of which are incorporated herein by reference intheir entirety.

The subject matter of the present application is related to thefollowing applications: 60/972,512; 60/972,329; 60/972,354; 60/972,616;60/972,343; 60/972,581; 60/972,629; 60/972,316; 60/972,333; 60/972,359;60/972,340 all of which were filed on Sep. 14, 2007; 61/046,196 filedApr. 18, 2008; 61/047,875 filed Apr. 25, 2008; 61/055,645 and 61/055,662both filed May 23, 2008; and 61/079,746 filed Jul. 10, 2008.

The following applications are being filed concurrently with the presentapplication, on Sep. 12, 2008; Ser. No. 12/209,279 entitled“Multi-Sensor Patient Monitor to Detect Impending Cardiac DecompensationPrediction”; Ser. No. 12/209,288 entitled “Adherent Device with MultiplePhysiological Sensors”; Ser. No. 12/209,430 entitled “Injectable Devicefor Physiological Monitoring”; Ser. No. 12/209,479 entitled “DeliverySystem for Injectable Physiological Monitoring System”; Ser. No.12/209,262 entitled “Adherent Device for Cardiac Rhythm Management”;Ser. No. 12/209,269 entitled “Adherent Athletic Monitor”; Ser. No.12/209,259 entitled “Adherent Emergency Monitor”; Ser. No. 12/209,273entitled “Adherent Device with Physiological Sensors”; Ser. No.12/209,276 entitled “Medical Device Automatic Start-up upon Contact toPatient Tissue”; Ser. No. 12/210,078 entitled “System and Methods forWireless Body Fluid Monitoring”; Ser. No. 12/209,265 entitled “AdherentCardiac Monitor with Advanced Sensing Capabilities”; Ser. No. 12/209,292entitled “Adherent Device for Sleep Disordered Breathing”; Ser. No.12/209,278 entitled “Dynamic Pairing of Patients to Data CollectionGateways”; Ser. No. 12/209,508 entitled “Adherent Multi-Sensor Devicewith Implantable Device Communications Capabilities”; Ser. No.12/202,528 entitled “Data Collection in a Multi-Sensor Patient Monitor”;Ser. No. 12/209,271 entitled “Adherent Multi-Sensor Device with EmpathicMonitoring”; Ser. No. 12/209,274 entitled “Energy Management forAdherent Patient Monitor”; and Ser. No. 12/209,294 entitled “Trackingand Security for Adherent Patient Monitor.”

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to systems and methods that usewireless physiological monitoring and more particularly to respiratorymonitoring. People need to breathe to stay alive. The medical term“apnea” refers to temporary cessation of respiration or breathing or anirregular breathing pattern. Some people do not have normal breathing,for example when they sleep, and monitoring breathing can be helpful todiagnose patients.

One conventional approach to diagnosis of sleep disorders has been torequire the patient to participate in a “sleep study.” The patient isoutfitted with an array of sensors attached to the surface of the bodyto monitor the patient's respiration, pulse, and blood oxygensaturation. A strip chart recorder can trace the sensor signals on paperfor later analysis by a health care professional.

Conventional sleep studies may have several shortcomings in at leastsome instances. The complexity and expense of the required equipment candictate that sleep studies be conducted in a clinic setting, i.e., ahospital or sleep laboratory. This can significantly increase the costsinvolved. In at least some instances, the patient may find it difficultto sleep in a strange setting, particularly while wearing sensorstethered by wires to a recorder, such as a strip chart recorder. In someinstances, respiration may be measured by requiring the patient to wearsensor devices applied to the face and body, which can especiallyuncomfortable to wear while trying to sleep.

With newer technology, sleep studies can be done in the home, but thismay still involve attaching various sensor devices and wires to the bodysurface. These tests may be single night events, and in at least someinstances may be too complex and expensive to be practical in monitoringtreatment efficacy and patient compliance over extended periods of time,such as days, weeks, or months.

One common treatment of sleep apnea may involve blowing air underpressure into the upper airway via a mask strapped to the face, whichmay be uncomfortable in at least some instances. Continuous positiveairway pressure (CPAP) and bi-level positive airway pressure (BiPAP) arethe treatment modalities that have been delivered by masks. Even thoughsleep apnea can be corrected with CPAP and BiPAP, both may haveexcessively high non-compliance rates due patient discomfort in at leastsome instances.

The apnea condition has become associated in recent years with thesudden infant death syndrome, or SIDS, in which an apparently healthyinfant dies of an unexplained cause. Although much research has beendone, many infants still die of this disease.

Cough can be a complaint of COPD (chronic obstructive pulmonary disease)patients (and other patients) that may impact sleep and cansignificantly impact quality of life at a functional, in at least someinstances.

Therefore, a need exists for improved sleep monitoring and management ofsleep disordered breathing, such as a respiration monitoring system fordiagnosis of sleep disorders that is suitable for use outside ofclinical settings, and which minimizes patient discomfort and can beused on patients of all ages from infant to adult. Ideally such, systemswould be less obtrusive to the patient than current, systems, andprovide monitoring that can be used to improve patient therapy.

2. Description of the Background Art

The following U.S. Patents and Publications may describe relevantbackground art: U.S. Pat. Nos. 4,121,573; 4,955,381; 4,981,139;5,080,099; 5,353,793; 5,511,553; 5,544,661; 5,558,638; 5,724,025;5,772,586; 5,862,802; 6,047,203; 6,117,077; 6,129,744; 6,225,901;6,385,473; 6,416,471; 6,454,707; 6,494,829; 6,527,711; 6,527,729;6,551,252; 6,595,927; 6,595,929; 6,605,038; 6,641,542; 6,645,153;6,821,249; 6,980,851; 7,020,508; 7,041,062; 7,054,679; 7,153,262;7,206,630; 7,297,119; 2003/0092975; 2005/0113703; 2005/0131288;2005/0137464; 2005/0277841; 2005/0277842; 2006/0010090; 2006/0031102;2006/0089679; 2006/122474; 2006/0155183; 2006/0161205; 2006/0173257;2006/0173269; 2006/0195144; 2006/0224051; 2006/0224072; 2006/0264730;2007/0021678; 2007/0038038; 2007/0073132; 2007/0123756; 2007/0129643;2007/0150008; and 2007/0255531.

BRIEF SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide animproved a respiratory monitoring system.

A further object of the present invention is to provide a respiratorymonitoring system that can be used for sleep studies, improved detectionof apnea, monitoring of apnea, monitoring of COPD, monitoring andtreatment of asthma, monitoring and treatment or orthopnea and otherrespiratory conditions.

A further object of the present invention is to provide a respiratorymonitoring system that uses outputs of a plurality of sensors withmultiple features to enhance physiological sensing performance.

Still a further object of the present invention is to provide arespiratory monitoring system where respiration status is determined bya weighted combination change in sensor outputs.

Yet another object of the present invention is to provide a respiratorymonitoring system where respiration status is determined when a rate ofchange of at least two sensor outputs is an abrupt change in the sensoroutputs as compared to a change in the sensor outputs over a longerperiod of time.

A further object of the present invention is to provide a respiratorymonitoring system where respiration status is determined by a tieredcombination of at least a first and a second sensor output, with thefirst sensor output indicating a problem that is then verified by atleast a second sensor output.

Another object of the present invention is to provide a respiratorymonitoring system where respiration status is determined by a variancefrom a baseline value of sensor outputs.

Yet another object of the present invention is to provide a respiratorymonitoring system where baseline values are defined by a look up table.

Still a further object of the present invention is to provide arespiratory monitoring system where respiration status is determinedwhen a first sensor output is at a high value that is greater than abaseline value, and at least one of a second a third sensor outputs isat a high value also sufficiently greater than a baseline value toindicate respiration status.

Another object of the present invention is to provide a respiratorymonitoring system where respiration status is determined by timeweighting the outputs of at least first, second and third sensors, andthe time weighting indicates a recent event that is indicative of therespiration status.

These and other objects of the present invention are achieved in manyembodiments that comprise a respiratory monitoring system. A detectingsystem is provided that includes, (i) an adherent device configured tobe coupled to a patient, the adherent device including a plurality ofsensors that monitor respiratory status, at least one of the sensorsconfigured to monitor the patient's respiration, and (ii) a wirelesscommunication device coupled to the plurality of sensors and configuredto transfer patient data directly or indirectly from the plurality ofsensors to a remote monitoring system. A remote monitoring system iscoupled to the wireless communication device.

In a first aspect, embodiments of the present invention provide arespiratory monitoring system for monitoring a patient. The respiratorymonitoring system comprises a patient detecting system, the patientdetecting system comprising an adherent device configured to couple to apatient. The adherent device comprises a plurality of sensors configuredto monitor physiological parameters of the patient to determinerespiratory status. At least one of the plurality of sensors isconfigured to monitor the patient's respiration. The adherent devicefurther comprises a wireless communication device coupled to theplurality of sensors. The respirator monitoring system further comprisesa remote monitoring system coupled to the wireless communication device.The wireless communication device is configured to transfer patient datafrom the plurality of sensors to the remote monitoring system.

The plurality of sensors may be configured to monitor respiration of thepatient with a bioimpedance sensor. The plurality of sensors maycomprise a combination of sensors. The combination of sensors comprisesas least one of a bioimpedance sensor, a heart rate sensor or a pulseoximeter sensor. The wireless communication device may be configured toreceive instructional data from the remote monitoring system.

In many embodiments, the respiratory monitoring system further comprisesa processor coupled to the plurality of sensors and to the wirelesscommunication device. The processor is configured to receive data fromthe plurality of sensors and process the patient data to generateprocessed patient data. The processor may be located at the remotemonitoring system. The patient detecting system may comprise amonitoring unit.

The remote monitoring system may comprise logic resources located at theremote monitoring system. The logic resources are configured todetermine a physiological event of the patient and determine therespiratory status of the patient. The monitoring unit may compriselogic resources configured to determine the respiratory status of thepatient and to determine a physiological event of a patient. Thephysiological event may comprise apnea.

The plurality of sensors may be configured to monitor respiration of thepatient with at least one of heart rate or pulse oximetry monitoring.The plurality of sensors may be configured to monitor respiration of thepatient with a bioimpedance sensor and at least one of heart ratemonitoring or pulse oximetry monitoring.

The adherent device may be configured to monitor the patient'srespiration continuously. The adherent device may be configured tomonitor a pulmonary disorder comprising at least one of chronicobstructive pulmonary disease, asthma or sleep disordered breathing.

The plurality of sensors may comprise a posture sensor for orthopneamonitoring. The posture sensor may comprise at least one of apiezoelectric accelerometer, capacitive accelerometer orelectromechanical accelerometer. The posture sensor may comprise a3-axis accelerometer.

The patient detecting system and the remote monitoring system may beconfigured to monitor the patient for a patient sleep study. Theplurality of sensors may comprise a patient movement sensor. The patientmovement sensor may comprise at least one of a piezoelectricaccelerometer, a capacitive accelerometer or an electromechanicalaccelerometer. The adherent device may comprise a plurality of patches.At least a first patch of the plurality is configured for placement athorax of the patient, and at least a second patch of the plurality isconfigured for placement at another patient site away from the thorax tomeasure patient movement.

In many embodiments, the respiratory monitoring system further comprisesa processor configured to determine the respiratory status in responseto a weighted combination of change in sensor outputs.

In many embodiments, the respiratory monitoring system further comprisesa processor configured to determine the respiratory status of thepatient when a rate of change of at least two sensor outputs comprisesan abrupt change in the sensor outputs as compared to a change in thesensor outputs over a longer period of time. The abrupt change maycomprise no more than about 10 seconds and the longer period of time maycomprise at least about one hour.

In many embodiments, the respiratory monitoring system further comprisesa processor configured to determine the respiratory status of thepatient in response to a tiered combination of at least a first sensoroutput and a second sensor output. The first sensor output indicates aproblem that is then verified by at least a second sensor output.

In many embodiments, the respiratory monitoring system further comprisesa processor configured to determine a physiological event of the patientin response to a variance from baseline values of sensor outputs. Thebaseline values may be defined by a look up table.

In many embodiments, the plurality of sensors may comprise at least afirst sensor, a second sensor and a third sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating one embodiment of a patientmonitoring system of the present invention;

FIGS. 2A and 2B illustrate an exploded view and side view of embodimentsof an adherent device with sensors configured to be coupled to the skinof a patient for monitoring purposes;

FIG. 3 illustrates one embodiment of an energy management device that iscoupled to the plurality of sensors of FIG. 1;

FIG. 4 illustrates one embodiment of present invention illustratinglogic resources configured to receive data from the sensors and/or theprocessed patient for monitoring purposes, analysis and/or predictionpurposes;

FIG. 5 illustrates an embodiment of the patient monitoring system of thepresent invention with a memory management device;

FIG. 6 illustrates an embodiment of the patient monitoring system of thepresent invention with an external device coupled to the sensors;

FIG. 7 illustrates an embodiment of the patient monitoring system of thepresent invention with a notification device;

FIG. 8 is a block diagram illustrating an embodiment of the presentinvention with sensor leads that convey signals from the sensors to amonitoring unit at the detecting system, or through a wirelesscommunication device to a remote monitoring system;

FIG. 9 is a block diagram illustrating an embodiment of the presentinvention with a control unit at the detecting system and/or the remotemonitoring system;

FIG. 10 is a block diagram illustrating an embodiment of the presentinvention where a control unit encodes patient data and transmits it toa wireless network storage unit at the remote monitoring system;

FIG. 11 is a block diagram illustrating one embodiment of an internalstructure of a main data collection station at the remote monitoringsystem of the present invention; and

FIG. 12 is a flow chart illustrating an embodiment of the presentinvention with operation steps performed by the system of the presentinvention in transmitting information to the main data collectionstation.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention comprise an adherent multi-sensorpatient monitor capable of tracking a patient's physiological statuswith a suite of sensors and wirelessly communicating with a remote site.The device may comprise specific sensors and algorithms for themonitoring and detection of pulmonary and breathing disorders.

An external, adherent patch device can be configured to be affixed tothe patient's thorax and may contain multiple physiological sensors. Thepatch can wirelessly communicate with a remote center, either directlyor indirectly via an intermediate device. The system can continuouslymonitor physiologic variables and issue patient and/or physician alertswhen appropriate.

The adherent patch device may directly and/or indirectly monitorrespiration with physiological sensors. Direct monitoring may comprisebioimpedance sensor measurements, for example. Indirect monitoring maycomprise at least one of heart rate measurements or pulse oximetrymonitoring measurements, for example.

Examples of target pulmonary disorders that can be monitored and/ortreated include chronic obstructive pulmonary disease, asthma, sleepdisordered breathing, such as apnea, dyspnea and orthopnea. Continuousphysiological monitoring of the patient with breathing disorders can beused.

Embodiments of the present invention may also be used for inpatientsleep studies, allowing for patient-friendly wireless monitoring. Thisembodiment may also include an activity sensor (either on the primarypatch or on a secondary, limb patch) to monitor the quality of thepatient's sleep.

In one embodiment, illustrated in FIG. 1, the present invention is apatient management system, generally denoted as 10, that tracks thepatient's physiological status, detects and predicts negativephysiological events. In one embodiment, a plurality of sensors are usedin combination to enhance detection and prediction capabilities as morefully explained below.

In one specific embodiment, the system 10 is a respiratory monitoringsystem. A detecting system including, denoted as 12, is provided. Thedetecting system includes, an adherent device configured to be coupledto a patient. The adherent device includes a plurality of sensors 14that monitor a patient's respiration. At least one of the sensorsmonitors the patient's respiration. In one embodiment, the adherentdevice includes a plurality of patches, with at least one patch at apatient's thorax, and at least one patch at another patient site tomeasure patient movement.

The detecting system 12 also includes a wireless communication device16, coupled to the plurality of sensors 14. The wireless communicationdevice transfers patient data directly or indirectly from the pluralityof sensors 14 to a remote monitoring system 18. The remote monitoringsystem 18 uses data from the sensors to determine respiratory status andpredict impending decompensation of the patient. The detecting system 12can continuously, or non-continuously, monitor the patient, alerts areprovided as necessary and medical intervention is provided whenrequired. In one embodiment, the wireless communication device 16 is awireless local area network for receiving data from the plurality ofsensors 12.

FIGS. 2A and 2B show embodiments of the plurality of sensors 14 withsupported with an adherent device 200 configured to adhere to the skin.The plurality of sensors 14 with an adherent device to the skin isprovided. As illustrated, a cover, batteries, electronics, including butnot limited to flex circuits and the like, an adherent tape, the actualsensors (electrodes) and hydrogels which interface the sensors 14 withthe skin, are provided. Adherent device 200 is described in U.S. App.No. 60/972,537, the full disclosure of which has been previouslyincorporated herein by reference. As illustrated in an exploded view ofthe adherent device, a cover 262, batteries 250, electronics 230,including but not limited to flex circuits and the like, an adherenttape 210T, the plurality of sensors may comprise electrodes and sensorcircuitry, and hydrogels which interface the plurality of sensors 14with the skin, are provided.

Adherent device 200 comprises a support, for example adherent patch 210,configured to adhere the device to the patient. Adherent patch 210comprises a first side, or a lower side 210A, that is oriented towardthe skin of the patient when placed on the patient and a second side, orupper side 210B, opposite of the first side. In many embodiments,adherent patch 210 comprises a tape 210T which is a material, preferablybreathable, with an adhesive 216A. Patient side 210A comprises adhesive216A to adhere the patch 210 and adherent device 200 to patient P.Electrodes 212A, 212B, 212C and 212D are affixed to adherent patch 210.In many embodiments, at least four electrodes are attached to the patch,for example six electrodes. In some embodiments the patch comprises twoelectrodes, for example two electrodes to measure the electrocardiogram(ECG) of the patient. Gel 214A, gel 214B, gel 214C and gel 214D can eachbe positioned over electrodes 212A, 212B, 212C and 212D, respectively,to provide electrical conductivity between the electrodes and the skinof the patient. In many embodiments, the electrodes can be affixed tothe patch 210, for example with known methods and structures such asrivets, adhesive, stitches, etc. In many embodiments, patch 210comprises a breathable material to permit air and/or vapor to flow toand from the surface of the skin. In some embodiments, a printed circuitboard (PCB), for example flex PCB 220, may be connected to upper side210B of patch 210 with connectors. In some embodiments, additionalPCB's, for example rigid PCB's 220A, 220B, 220C and 220D, can beconnected to flex PCB 220. Electronic components 230 can be connected toflex PCB 220 and/or mounted thereon. In some embodiments, electroniccomponents 230 can be mounted on the additional PCB's.

Electronic circuitry and components 230 comprise circuitry andcomponents to take physiologic measurements, transmit data to remotecenter and receive commands from remote center. In many embodiments,electronics components 230 may comprise known low power circuitry, forexample complementary metal oxide semiconductor (CMOS) circuitrycomponents. Electronics components 230 comprise an activity sensor andactivity circuitry, impedance circuitry and electrocardiogram circuitry,for example ECG circuitry. In some embodiments, electronics circuitrymay comprise a microphone and microphone circuitry to detect an audiosignal from within the patient, and the audio signal may comprise aheart sound and/or a respiratory sound, for example an S3 heart soundand a respiratory sound with rales and/or crackles. Electronicscircuitry and components 230 may comprise a temperature sensor, forexample a thermistor, and temperature sensor circuitry to measure atemperature of the patient, for example a temperature of a skin of thepatient.

A cover 262 can extend over the batteries, electronic components andflex printed circuit board. In many embodiments, an electronics housing260 may be disposed under cover 262 to protect the electroniccomponents, and in some embodiments electronics housing 260 may comprisean encapsulant over the electronic components and PCB. In someembodiments, cover 262 can be adhered to adhesive patch with anadhesive. In many embodiments, electronics housing 260 may comprise awater proof material, for example a sealant adhesive such as epoxy orsilicone coated over the electronics components and/or PCB. In someembodiments, electronics housing 260 may comprise metal and/or plastic.Metal or plastic may be potted with a material such as epoxy orsilicone.

Cover 262 may comprise many known biocompatible cover, casing and/orhousing materials, such as elastomers, for example silicone. Theelastomer may be fenestrated to improve breathability. In someembodiments, cover 262 may comprise many known breathable materials, forexample polyester, polyamide, and/or elastane (Spandex). The breathablefabric may be coated to make it water resistant, waterproof, and/or toaid in wicking moisture away from the patch.

Adherent device 200 comprises several layers. Gel 214A, or gel layer, ispositioned on electrode 212A to provide electrical conductivity betweenthe electrode and the skin. Electrode 212A may comprise an electrodelayer. Adhesive patch 210 may comprise a layer of breathable tape 210T,for example a known breathable tape, such as tricot-knit polyesterfabric. In many embodiments, a gap 269 extends from adhesive patch 210to the electronics circuitry and components 230, such that breathabletape 210T can breathe to provide patient comfort. An adhesive 216A, forexample a layer of acrylate pressure sensitive adhesive, can be disposedon underside 210A of patch 210. A gel cover 280, or gel cover layer, forexample a polyurethane non-woven tape, can be positioned over patch 210comprising the breathable tape. A PCB layer, for example flex PCB 220,or flex PCB layer, can be positioned over gel cover 280 with electroniccomponents 230 connected and/or mounted to flex PCB 220, for examplemounted on flex PCB so as to comprise an electronics layer disposed onthe flex PCB. In many embodiments, the adherent device may comprise asegmented inner component, for example the PCB, for limited flexibility.In many embodiments, the electronics layer may be encapsulated inelectronics housing 260 which may comprise a waterproof material, forexample silicone or epoxy. In many embodiments, the electrodes areconnected to the PCB with a flex connection, for example a trace 222A offlex PCB 220, so as to provide strain relief between the electrodes212A, 212B, 212C and 212D and the PCB. Gel cover 280 can inhibit flow ofgel 214A and liquid. In many embodiments, gel cover 280 can inhibit gel214A from seeping through breathable tape 210T to maintain gel integrityover time. Gel cover 280 can also keep external moisture frompenetrating into gel 214A. Gel cover 280 may comprise at least oneaperture 280A sized to receive one of the electrodes. In manyembodiments, cover 262 can encase the flex PCB and/or electronics andcan be adhered to at least one of the electronics, the flex PCB or theadherent patch, so as to protect the device. In some embodiments, cover262 attaches to adhesive patch 210 with adhesive 216B or adhesive 264.Cover 262 can comprise many known biocompatible cover, housing and/orcasing materials, for example silicone. In many embodiments, cover 262comprises an outer polymer cover to provide smooth contour withoutlimiting flexibility. In some embodiments, cover 262 may comprise abreathable fabric. Cover 262 may comprise many known breathable fabrics,for example breathable fabrics as described above. In some embodiments,the breathable fabric may comprise polyester, polyamide, and/or elastane(Spandex™) to allow the breathable fabric to stretch with body movement.In some embodiments, the breathable tape may contain and elute apharmaceutical agent, such as an antibiotic, anti-inflammatory orantifungal agent, when the adherent device is placed on the patient.

The patient's respiration can be measured by a variety of meansincluding but not limited to, a bioimpedance sensor, heart rate, pulseoximetry monitoring and the like. In one embodiment, the patient'srespiration is continuously monitored. The respiration can be monitoredto monitor a number of disorders including but not limited to, chronicobstructive pulmonary disease, asthma, sleep disordered breathing andthe like. In one specific embodiment, the patient's respiration ismonitored for a patient's sleep study. One of the sensors 14 can be apatient movement sensor. Respiration sensing can be used in conjunctionwith a posture sensor, including but not limited to a 3-axisaccelerometer, to detect orthopnea. Respiration sensing can be inconjunction with HR sensing. The system can be used for, sleep studies,improved detection of apnea, monitoring of apnea, monitoring of COPD,monitoring and treatment of asthma, monitoring and treatment oforthopnea and other respiratory conditions.

Referring to FIG. 3, an energy management device 19 can be coupled tothe plurality of sensors. In one embodiment, the energy managementdevice 19 is part of the detecting system. In various embodiments, theenergy management device 19 performs one or more of modulate drivelevels per sensed signal of a sensor 14, modulate a clock speed tooptimize energy, watch cell voltage drop—unload cell, coulomb-meter orother battery monitor, sensor dropoff at an end of life of a batterycoupled to a sensor, battery end of life dropoff to transfer data,elective replacement indicator, call center notification, sensingwindows by the sensors 14 based on a monitored physiological parameterand sensing rate control.

In one embodiment, the energy management device 19 is configured tomanage energy by at least one of, a thermo-electric unit, kinetics, fuelcell, through solar power, a zinc air interface, Faraday generator,internal combustion, nuclear power, a micro-battery and with arechargeable device.

The system 10 is configured to automatically detect events. The system10 automatically detects events by at least one of, high noise states,physiological quietness, sensor continuity and compliance. In responseto a detected physiological event, patient states are identified whendata collection is inappropriate. In response to a detectedphysiological event, patient states are identified when data collectionis desirable. Patient states include, physiological quietness, rest,relaxation, agitation, movement, lack of movement and a patient's higherlevel of patient activity.

The system can use an intelligent combination of sensors to enhancedetection and prediction capabilities, as more fully discloses in U.S.patent application Ser. No. 60/972,537, previously incorporated hereinby reference, and as more fully explained below.

In one embodiment, the detecting system 12 communicates with the remotemonitoring system 18 periodically or in response to a trigger event. Thetrigger event can include but is not limited to at least one of, time ofday, if a memory is full, if an action is patient initiated, if anaction is initiated from the remote monitoring system, a diagnosticevent of the monitoring system, an alarm trigger, a mechanical trigger,and the like.

The adherent device be activated by a variety of different meansincluding but not limited to, a physiological trigger, automaticimpedance, a tab pull, battery insertion, a hall or reed switch, abreakable glass capsule, a dome switch, by light activation, pressureactivation, body temperature activation, a connection betweenelectronics associated with the sensors and the adherent device,exposure to air, by a capacitive skin sensor and the like.

The detecting system 12 can continuously, or non-continuously, monitorthe patient, alerts are provided as necessary and medical interventionis provided when required. In one embodiment, the wireless communicationdevice 16 is a wireless local area network for receiving data from theplurality of sensors.

A processor 20 is coupled to the plurality of sensors 14 and can also bea part of the wireless communication device 16. The processor 20receives data from the plurality of sensors 14 and creates processedpatient data. In one embodiment, the processor 20 is at the remotemonitoring system. In another embodiment, the processor 20 is at thedetecting system 12. The processor 20 can be integral with a monitoringunit 22 that is part of the detecting system 12 or part of the remotemonitoring system.

The processor 20 has program instructions for evaluating values receivedfrom the sensors 14 with respect to acceptable physiological ranges foreach value received by the processor 20 and determine variances. Theprocessor 20 can receive and store a sensed measured parameter from thesensors 14, compare the sensed measured value with a predeterminedtarget value, determine a variance, accept and store a new predeterminedtarget value and also store a series of questions from the remotemonitoring system 18.

Referring to FIG. 4, logic resources 24 are provided that take the datafrom the sensors 14, and/or the processed patient data from theprocessor 20, to predict an impending decompensation. The logicresources 24 can be at the remote monitoring system 18 or at thedetecting system 12, such as in the monitoring unit 22.

In one embodiment, a memory management device 25 is provided as shown inFIG. 5. In various embodiments, the memory management device 25 performsone or more of data compression, prioritizing of sensing by a sensor 14,monitoring all or some of sensor data by all or a portion of the sensors14, sensing by the sensors 14 in real time, noise blanking to providethat sensor data is not stored if a selected noise level is determined,low-power of battery caching and decimation of old sensor data.

The sensors 14 can provide a variety of different functions, includingbut not limited to, initiation, programming, measuring, storing,analyzing, communicating, predicting, and displaying of a physiologicalevent of the patient. A wide variety of different sensors 14 can beutilized, including but not limited to, bioimpedance, heart rate, heartrhythm, HRV, HRT, heart sounds, respiration rate, respiration ratevariability, respiratory sounds, Sp02, blood pressure, activity,posture, wake/sleep, orthopnea, temperature, heat flux and anaccelerometer. A variety activity sensors can be utilized, including butnot limited to a, ball switch, accelerometer, minute ventilation, HR,bioimpedance noise, skin temperature/heat flux, BP, muscle noise,posture and the like.

The outputs of the sensors 14 can have multiple features to enhancephysiological sensing performance. These multiple features have multiplesensing vectors that can include redundant vectors. The sensors caninclude current delivery electrodes and sensing electrodes. Size andshape of current delivery electrodes, and the sensing electrodes, can beoptimized to maximize sensing performance. The system 10 can beconfigured to determine an optimal sensing configuration andelectronically reposition at least a portion of a sensing vector of asensing electrode. The multiple features enhance the system's 10 abilityto determine an optimal sensing configuration and electronicallyreposition sensing vectors. In one embodiment, the sensors 14 can bepartially masked to minimize contamination of parameters sensed by thesensors 14.

The size and shape of current delivery electrodes, for bioimpedance, andsensing electrodes can be optimized to maximize sensing performance.Additionally, the outputs of the sensors 14 can be used to calculate andmonitor blended indices. Examples of the blended indices include but arenot limited to, heart rate (HR) or respiratory rate (RR) response toactivity, HR/RR response to posture change, HR+RR, HR/RR+bioimpedance,and/or minute ventilation/accelerometer and the like.

The sensors 14 can be cycled in order to manage energy, and differentsensors 14 can sample at different times. By way of illustration, andwithout limitation, instead of each sensor 14 being sampled at aphysiologically relevant interval, e.g. every 30 seconds, one sensor 14can be sampled at each interval, and sampling cycles between availablesensors.

By way of illustration, and without limitation, the sensors 14 cansample 5 seconds for every minute for ECG, once a second for anaccelerometer sensor, and 10 seconds for every 5 minutes for impedance.

In one embodiment, a first sensor 14 is a core sensor 14 thatcontinuously monitors and detects, and a second sensor 14 verifies aphysiological status in response to the core sensor 14 raising a flag.Additionally, some sensors 14 can be used for short term tracking, andother sensors 14 used for long term tracking.

Referring to FIG. 6, in one embodiment, an external device 38, includinga medical treatment device, is coupled to the sensors 14. The externaldevice 38 can be coupled to a monitoring unit 22 that is part of thedetecting system 12, or in direct communication with the sensors 14. Avariety of different external devices 38 can be used, including but notlimited to, a weight scale, blood pressure cuff, cardiac rhythmmanagement device, a medical treatment device, medicament dispenser andthe like). Suitable cardiac rhythm management devices include but arenot limited to, Boston Scientific's Latitude system, Medtronic'sCareLink system, St. Jude Medical's HouseCall system and the like. Suchcommunication may occur directly, or via an external translator unit.

The external device 38 can be coupled to an auxiliary input of themonitoring unit 22 at the detecting system 12 or to the monitoringsystem 22 at the remote monitoring system 18. Additionally, an automatedreader can be coupled to an auxiliary input in order to allow a singlemonitoring unit 22 to be used by multiple patients. As previouslymentioned above, the monitoring unit 22 can be at the remote monitoringsystem 18 and each patient can have a patient identifier (ID) includinga distinct patient identifier. In addition, the ID identifier can alsocontain patient specific configuration parameters. The automated readercan scan the patient identifier ID and transmit the patient ID numberwith a patient data packet such that the main data collection stationcan identify the patient.

It will be appreciated that other medical treatment devices can also beused. The sensors 14 can communicate wirelessly with the externaldevices 38 in a variety of ways including but not limited to, a publicor proprietary communication standard and the like. The sensors 14 canbe configured to serve as a communication hub for multiple medicaldevices, coordinating sensor data and therapy delivery whiletransmitting and receiving data from the remote monitoring system 18.

In one embodiment, the sensors 14 coordinate data sharing between theexternal systems 38 allowing for sensor integration across devices. Thecoordination of the sensors 14 provides for new pacing, sensing,defibrillation vectors and the like.

In one embodiment, the processor 20 is included in the monitoring unit22 and the external device 38 is in direct communication with themonitoring unit 22.

Referring to FIG. 7, in another embodiment, a notification device 42 iscoupled to the detecting system 12 and the remote monitoring system 18.The notification device 42 is configured to provide notification whenvalues received from the sensors 14 are not within acceptablephysiological ranges. The notification device 42 can be at the remotemonitoring system 18 or at the monitoring unit 22 that is part of thedetecting system 12. A variety of notification devices 42 can beutilized, including but not limited to, a visible patient indicator, anaudible alarm, an emergency medical service notification, a call centeralert, direct medical provider notification and the like. Thenotification device 42 provides notification to a variety of differententities, including but not limited to, the patient, a caregiver, theremote monitoring system, a spouse, a family member, a medical provider,from one device to another device such as the external device 38, andthe like.

Notification can be according to a preset hierarchy. By way ofillustration, and without limitation, the preset hierarchy can be,patient notification first and medical provider second, patientnotification second and medical provider first, and the like. Uponreceipt of a notification, a medical provider, the remote monitoringsystem 18, or a medical treatment device can trigger a high-ratesampling of physiological parameters for alert verification.

The system 10 can also include an alarm 46, that can be coupled to thenotification device 42, for generating a human perceptible signal whenvalues received from the sensors 14 are not within acceptablephysiological ranges. The alarm 46 can trigger an event to rendermedical assistance to the patient, provide notification as set forthabove, continue to monitor, wait and see, and the like.

When the values received from the sensors 14 are not within acceptablephysiological ranges the notification is with the at least one of, thepatient, a spouse, a family member, a caregiver, a medical provider andfrom one device to another device, to allow for therapeutic interventionto prevent decompensation, and the like.

In another embodiment, the sensors 14 can switch between differentmodes, wherein the modes are selected from at least one of, a standalone mode with communication directly with the remote monitoring system18, communication with an implanted device, communication with a singleimplanted device, coordination between different devices (externalsystems) coupled to the plurality of sensors and different devicecommunication protocols.

Respiratory status can be determined by a weighted combination change insensor outputs and be determined by a number of different means,including but not limited to, (i) when a rate of change of at least twosensor outputs is an abrupt change in the sensor outputs as compared toa change in the sensor outputs over a longer period of time, (ii) by atiered combination of at least a first and a second sensor output, withthe first sensor output indicating a problem that is then verified by atleast a second sensor output, (iii) by a variance from a baseline valueof sensor outputs, and the like. The baseline values can be defined in alook up table.

In another embodiment, respiratory status is determined using three ormore sensors by at least one of, (i) when the first sensor output is ata value that is sufficiently different from a baseline value, and atleast one of the second and third sensor outputs is at a value alsosufficiently different from a baseline value to indicate respiratorystatus, (ii) by time weighting the outputs of the first, second andthird sensors, and the time weighting indicates a recent event that isindicative of the respiratory status and the like.

In one embodiment, the wireless communication device 16 can include a,modem, a controller to control data supplied by the sensors 14, serialinterface, LAN or equivalent network connection and a wirelesstransmitter. Additionally, the wireless communication device 16 caninclude a receiver and a transmitter for receiving data indicating thevalues of the physiological event detected by the plurality of sensors,and for communicating the data to the remote monitoring system 18.Further, the wireless communication device 16 can have data storage forrecording the data received from the sensors 14 and an access device forenabling access to information recording in the data storage from theremote monitoring system 18.

EXAMPLE 1 Sleep Apnea

Sleep apnea is a disorder characterized by a reduction or cessation(pause of breathing, airflow) during sleep. It is common among adultsbut rare among children. There are two types of sleep apnea, the morecommon obstructive sleep apnea and the less common central sleep apnea,both of which will be described later in this article. Although adiagnosis of sleep apnea often will be suspected on the basis of aperson's history, there are several tests that can be used to confirmthe diagnosis. The treatment of sleep apnea may be either surgical ornonsurgical.

An apnea is a period of time during which breathing stops or is markedlyreduced. In simplified terms, an apnea occurs when a person stopsbreathing for 10 seconds or more. So, if normal breath airflow is 70% to100%, an apnea is if you stop breathing completely, or take less than25% of a normal breath (for a period that lasts 10 seconds or more).This definition includes complete stoppage of airflow. Other definitionsof apnea that may be used include at least a 4% drop in the saturationof oxygen in the blood, a direct result of the reduction in the transferof oxygen into the blood when breathing stops.

Apneas usually occur during sleep. When an apnea occurs, sleep isdisrupted. Sometimes this means the person wakes up completely, butsometimes this can mean the person comes out of a deep level of sleepand into a more shallow level of sleep. Apneas are usually measuredduring sleep (preferably in all stages of sleep) over a two-hour period.An estimate of the severity of apnea is calculated by dividing thenumber of apneas by the number of hours of sleep, giving an apnea index(AI). The greater the AI, the more severe the apnea.

A hypopnea is a decrease in breathing that is not as severe as an apnea.So, if normal breath airflow is 100% to 70%, a hypopnea is 69% to 26% ofa normal breath. Like apneas, hypopneas are associated with a 4% orgreater drop in the saturation of oxygen in the blood and usually occurduring sleep. Also like apneas, hypopneas usually disrupt the level ofsleep. A hypopnea index (HI) can be calculated by dividing the number ofhypopneas by the number of hours of sleep.

The apnea-hypopnea index (AHI) is an index of severity that combinesapneas and hypopneas. Combining them both gives an overall severity ofsleep apnea including sleep disruptions and desaturations (a low levelof oxygen in the blood). The apnea-hypopnea index, like the apnea indexand hypopnea index, is calculated by dividing the number of apneas andhypopneas by the number of hours of sleep. Another index that is used tomeasure sleep apnea is the respiratory disturbance index (RDI). Therespiratory disturbance index is similar to the apnea-hypopnea index,however, it also includes respiratory events that do not technicallymeet the definitions of apneas or hypopneas, but do disrupt sleep.

Sleep apnea is formally defined as an apnea-hypopnea index of at least15 episodes/hour in a patient without medical problems that may berelated to the sleep apnea. That is the equivalent of one episode every4 minutes. In a patient with high blood pressure, stroke, daytimesleepiness, ischemic heart disease (low flow of blood to the heart),insomnia, or mood disorders—all of which can be caused or worsened bysleep apnea—sleep apnea is defined as an apnea-hypopnea index of atleast 5 episodes/hour. This definition is stricter because the patientmay be already experiencing the negative medical effects of sleep apnea,and it may be important to begin treatment at a lower apnea-hypopneaindex.

The system 10 of the present invention is used for detecting apnea andrespiratory arrest. An alarm can be provided to wake the individual orto summon help to restore a normal breathing cycle. The system sensesthe cyclical rhythm of an individual's breathing.

The system 10 includes logic resources that incorporates a firstpreselected or predetermined time, which for purpose of illustration canbe about twenty minutes. Then, when the system 10 detects anindividual's cyclical rhythm of breathing for that period of time, thesystem can arm the alarm.

The system 10 detects an interruption in the breathing cycle and timesthe interruption in the cyclical rhythm of breathing. If theinterruption of the breathing cycle continues for a period of time, anynumber of different actions can be taken to jar the patient into anawakened state.

EXAMPLE 2 Sleep Study and Multiple Sleep Latency Test or MSLT

A Sleep Study or Polysomnogram (PSG) is a multiple-component test, whichelectronically transmits and records specific physical activities whileyou sleep. The recordings become data, which are read or analyzed by aqualified physician to determine is a patient has a sleep disorder.

Generally, there are four types of Polysomnographic Studies. They are:

Diagnostic Overnight PSG—General monitoring and evaluation.

Diagnostic Daytime Multiple Sleep Latency Test (MSLT)—Used to diagnoseNarcolepsy and measure the degree of daytime sleepiness. To ensureaccurate results, it is performed on the morning following a DiagnosticOvernight PSG.

Two Night PSG with CPAP Titration—General monitoring and diagnosticevaluation is conducted on the first night. If Sleep Apnea isdiscovered, the patient returns for a second night to determine thenecessary CPAP pressure required to alleviate apnea.

Split Night PSG with CPAP Titration—Split Night PSG is conducted whenmoderate or severe Sleep Apnea has been discovered or strongly suspectedduring the first part of the nights study. The second half of the nightis used for CPAP Titration.

The system 10 is used in a sleep study for a patient to determine if thepatient has sleep apnea. The patient is coupled to sensors, monitoringdevices, from the system 10, and the like, during a setup can take 30-45minutes or more in order to get everything connected properly. Belts areplaced around the patient's chest and abdomen to measure respiratoryefforts, and a band-aid like oximeter probe is placed on the patient'sfinger to measure the amount of oxygen. The sensors or electrodes fromsystem 10 are adhered to the patient's skin and scalp.

Recorded electrical signals generated by the patient's brain and muscleactivity are sent to the system 10 and are recorded digitally and oncontinuous strips of paper. The pattern of this activity is recognizedby a sleep specialist who reads or interprets the study.

An EEG, or electroencephalogram, is a major part of the sleep study. Itmeasures and records four forms of brain wave activity—alpha, beta,delta and theta waves. Alpha waves are usually found during relaxedwakefulness, particularly when the patient's eyes are closed. Thetawaves are seen during the lighter sleep stages 1 and 2, while deltawaves occur chiefly in deep sleep, the so-called “slow wave sleep” foundin sleep stages 3 and 4.

An EMG, or electromyogram, records muscle activity such as facetwitches, teeth grinding, and leg movements. It also helps indetermining the presence of REM stage sleep. The amount and duration ofthese activities provides the doctor important information about thepatient's sleep. An EOG or electro-oculogram, records eye movements.These movements are important in determining the different sleep stages,particularly REM stage sleep. The electrodes are usually placed on theouter aspect of your right eyebrow and along the outer aspect below orbeneath the left eye.

An EKG, or electrocardiogram records heart activities, such as rate andrhythm. Electrodes are placed on the patient's chest. A nasal airflowsensor records breath temperature, airflow, apnea and hypopnea events. Asensor is placed near the patient's nose and mouth. Chest/abdomen beltsare used to record breathing depth, apnea and hypopnea events. Elasticbelts are placed around the patient's chest and abdomen. An oximeterrecords blood oxygen saturation. A band-aid like clip is placed on afinger. Video is used to records body positioning and movements. A snoremicrophone is used to record snoring. An electrode is placed over thepatient's trachea, on the lower neck.

Sleeping is a complex activity that must occur for a successfulpolysomnographic study. During sleep, our brain and body cycle betweenNREM and REM sleep approximately every 90 minutes.

During these transitions, major changes occur in EEG, EOG, EMG,heartrate and respiration that are necessary for healthy sleep. Ifabnormal changes are observed during a particular sleep stage, then thesystem 10 defines this problem as it occurs during the night.

Elastic belts are placed around the patient's and abdomen to recordbreathing rate and effort from the diaphragm, as well as apnea andhypopnea events.

A Multiple Sleep Latency Test, or MSLT, is designed to measure thedegree of sleep tendency or sleepiness in a given patient. This test isconducted during the day, with the system 10, following a routine PSGand features a series of up to 5 naps, each lasting usually less than 30minutes that are timed to start every two hours during the day. Forexample, 10 am, 12(noon), 2 pm, 4 pm and 6 pm represent a possible napschedule.

The purpose of the MSLT is two fold: first, to average the number ofminutes that it takes to fall asleep (sleep onset latency) during allthe naps and second, to record if REM stage sleep occurs during any ofthese scheduled napping periods. The testing procedure includesessentially the same PSG leads as for a diagnostic overnight study.During the periods between naps, the patient stays awake and does notfall asleep.

This test is particularly useful in determining if a patient withnarcolepsy is adjusting to its medication, diagnose Narcolepsy,objectively quantify the degree of sleepiness in a particular patient,such as an OSA (obstructive sleep apnea) patient who is still sleepydespite CPAP treatment and in diagnosing Idiopathic Hypersomnolence.

EXAMPLE 3 COPD

Patients with mild to severe COPD are monitored in their homesperforming their normal daily activities (including sleep) using thesystem 10. RC and an AB RIP band sensors, a modified limb II ECG sensor,an accelerometer sensor, filtered for posture and movement, are used toidentify cough sounds. During sleep, data from associated EEG and EOGsensors is also recorded. This physiological monitoring data wasprocessed by the remote monitoring system 18.

Results of these measurements indicated that cough frequency followedcircadian patterns. Nocturnal cough occurred at a significant frequencythroughout most of the night except the early morning. A number of thesenocturnal coughs occurred during an EEG arousal or within a permissibletime window associated with an arousal. The number of coughs during eachsleep stage is determined. COPD patients experienced cough evenlydistributed throughout both stages 3 and 4 of NREM sleep and also REMsleep. However, during NREM stage 1, coughs are somewhat increased; andduring NREM stage 2, an exceptional number of coughs occurred. Thus,nocturnal cough occurred most frequently during the lighter sleepstages, and hence these COPD patients spent a greater than normalpercentage of time in stage 1 sleep.

Thus, nocturnal cough is preventing these COPD patients from progressingnaturally to deeper sleep stages, leading a disruption of sleeparchitecture in which an unusual percentage of time is spent in stage 1and 2 sleep.

EXAMPLE 4 Orthopnea

By way of illustration, orthopnea, or paroxysmal nocturnal dyspnea(“PND”) of a patient is monitored. The processor 20 compares at leasttwo respiration patterns. The non-recumbent respiration pattern showsthat the patient is taking relatively slow and deep breaths as can beseen by the relatively low frequency and high amplitude of the pattern.However, the recumbent respiration pattern shows that the patient istaking relatively rapid and shallow breaths as indicated by therelatively high frequency and low amplitude of the pattern. The rapidand shallow breathing of the recumbent respiration pattern indicates apatient suffering from orthopnea that eventually occurs upon lying down.

The presence of orthopnea is known to be a sign of congestion. However,other recumbent respiration pattern changes resulting from lying downmay also be indicative of congestion. Therefore, the processor 20 mayperform various comparisons in addition to or as an alternative tolooking for both rapid and shallow breaths. For example, the processor20 may search for only rapid recumbent respiration relative to uprightrespiration. Similarly, the processor 20 may search for only shallow, orlow tidal volume, recumbent respiration relative to upright respiration.As another example, the processor 20 may search for a difference in thecombination of respiratory rate to tidal volume between tile recumbentand non-recumbent respiration patterns. Such a combination may be aratio of respiratory rate to tidal volume. Additionally, the processor20 may search for a difference in inspiration times and expiratorytimes, inspiration time of a recumbent pattern versus inspiratory for anon-recumbent pattern, and/or expiratory time of a recumbent patternversus expiratory time of a non-recumbent pattern.

In various embodiments, the remote monitoring system 18 can include areceiver, a transmitter and a display for displaying data representativeof values of the one physiological event detected by the sensors 14. Theremote monitoring system can also include a, data storage mechanism thathas acceptable ranges for physiological values stored therein, acomparator for comparing the data received from the monitoring system 12with the acceptable ranges stored in the data storage device and aportable computer. The remote monitoring system 18 can be a portableunit with a display screen and a data entry device for communicatingwith the wireless communication device 16.

Referring now to FIG. 8, for each sensor 14, a sensor lead 112 and 114conveys signals from the sensor 14 to the monitoring unit 22 at thedetecting system 12, or through the wireless communication device 16 tothe remote monitoring system 18. In one embodiment, each signal from asensor 14 is first passed through a low-pass filter 116, at thedetecting system 12 or at the remote monitoring system 18, to smooth thesignal and reduce noise. The signal is then transmitted to ananalog-to-digital converter 118A, which transforms the signals into astream of digital data values that can be stored in a digital memory118B. From the digital memory 118B, data values are transmitted to adata bus 120, along which they are transmitted to other components ofthe circuitry to be processed and archived. From the data bus 120, thedigital data can be stored in a non-volatile data archive memory. Thedigital data can be transferred via the data bus 120 to the processor20, which processes the data based in part on algorithms and other datastored in a non-volatile program memory.

The detecting system 12 can also include a power management module 122configured to power down certain components of the system, including butnot limited to, the analog-to-digital converters 118A, digital memories118B and the non-volatile data archive memory and the like, betweentimes when these components are in use. This helps to conserve batterypower and thereby extend the useful life. Other circuitry and signalingmodes may be devised by one skilled in the art.

As can be seen in FIG. 9, a control unit 126 is included at thedetecting system 12, the remote monitoring system 18 or at bothlocations.

In one embodiment, the control unit 126 can be a 486 microprocessor,available from Intel, Inc. of Santa Clara, Calif. The control unit 126can be coupled to the sensors 14 directly at the detecting system 12,indirectly at the detecting system 12 or indirectly at the remotemonitoring system 18. Additionally the control unit 126 can be coupledto a blood pressure monitor, a cardiac rhythm management device, a scaleor a device that dispenses medication that can indicate the medicationhas been dispensed.

The control unit 126 can be powered by AC inputs which are coupled tointernal AC/DC converters 134 that generate multiple DC voltage levels.After the control unit 126 has collected the patient data from thesensors 14, the control unit 126 encodes the recorded patient data andtransmits the patient data through the wireless communication device 16to transmit the encoded patient data to a wireless network storage unit128 at the remote monitoring system 18 as shown in FIG. 10. In anotherembodiment, wireless communication device 16 transmits the patient datafrom the sensors 14 to the control unit 126 when it is at the remotemonitoring system 18.

Every time the control unit 126 plans to transmit patient data to a maindata collection station 130, located at the remote monitoring system 18,the control unit 126 attempts to establish a communication link. Thecommunication link can be wireless, wired, or a combination of wirelessand wired for redundancy, e.g., the wired link checks to see if awireless communication can be established. If the wireless communicationlink 16 is available, the control unit 126 transmits the encoded patientdata through the wireless communication device 16. However, if thewireless communication device 16 is not available for any reason, thecontrol unit 126 waits and tries again until a link is established.

Referring now to FIG. 11, one embodiment of an internal structure of amain data collection station 130, at the remote monitoring system 18, isillustrated. The patient data can be transmitted by the remotemonitoring system 18 by either the wireless communication device 16 orconventional modem to the wireless network storage unit 128. Afterreceiving the patient data, the wireless network storage unit 128 can beaccessed by the main data collection station 130. The main datacollection station 130 allows the remote monitoring system 18 to monitorthe patient data of numerous patients from a centralized locationwithout requiring the patient or a medical provider to physicallyinteract with each other.

The main data collection station 130 can include a communications server136 that communicates with the wireless network storage unit 128. Thewireless network storage unit 128 can be a centralized computer serverthat includes a unique, password protected mailbox assigned to andaccessible by the main data collection station 130. The main datacollection station 130 contacts the wireless network storage unit 128and downloads the patient data stored in a mailbox assigned to the maindata collection station 130.

Once the communications server 136 has formed a link with the wirelessnetwork storage unit 128, and has downloaded the patient data, thepatient data can be transferred to a database server 138. The databaseserver 138 includes a patient database 140 that records and stores thepatient data of the patients based upon identification included in thedata packets sent by each of the monitoring units 22. For example, eachdata packet can include an identifier.

Each data packet transferred from the remote monitoring system 18 to themain data collection station 130 does not have to include any patientidentifiable information. Instead, the data packet can include theserial number assigned to the specific detecting system 12. The serialnumber associated with the detecting system 12 can then be correlated toa specific patient by using information stored on the patient database138. In this manner, the data packets transferred through the wirelessnetwork storage unit 128 do not include any patient-specificidentification. Therefore, if the data packets are intercepted orimproperly routed, patient confidentiality can not be breached.

The database server 138 can be accessible by an application server 142.The application server 142 can include a data adapter 144 that formatsthe patient data information into a form that can be viewed over aconventional web-based connection. The transformed data from the dataadapter 144 can be accessible by propriety application software througha web server-146 such that the data can be viewed by a workstation 148.The workstation 148 can be a conventional personal computer that canaccess the patient data using proprietary software applications through,for example, HTTP protocol, and the like.

The main data collection station further can include an escalationserver 150 that communicates with the database server 138. Theescalation server 150 monitors the patient data packets that arereceived by the database server 138 from the monitoring unit 22.Specifically, the escalation server 150 can periodically poll thedatabase server 138 for unacknowledged patient data packets. The patientdata packets are sent to the remote monitoring system 18 where theprocessing of patient data occurs. The remote monitoring system 18communicates with a medical provider if the event that an alert isrequired. If data packets are not acknowledged by the remote monitoringsystem 18, the escalation server 150 can be programmed to automaticallydeliver alerts to a specific medical provider if an alarm message hasnot been acknowledged within a selected time period after receipt of thedata packet.

The escalation server 150 can be configured to generate the notificationmessage to different people by different modes of communication afterdifferent delay periods and during different time periods.

The main data collection station 130 can include a batch server 152connected to the database server 138. The batch server 152 allows anadministration server 154 to have access to the patient data stored inthe patient database 140. The administration server allows forcentralized management of patient information and patientclassifications.

The administration server 154 can include a batch server 156 thatcommunicates with the batch server 152 and provides the downloaded datato a data warehouse server 158. The data warehouse server 158 caninclude a large database 160 that records and stores the patient data.

The administration server 154 can further include an application server162 and a maintenance workstation 164 that allow personnel from anadministrator to access and monitor the data stored in the database 160.

The data packet utilized in the transmission of the patient data can bea variable length ASCII character packet, or any generic data formats,in which the various patient data measurements are placed in a specificsequence with the specific readings separated by commas. The controlunit 126 can convert the readings from each sensor 14 into astandardized sequence that forms part of the patient data packet. Inthis manner, the control unit 126 can be programmed to convert thepatient data readings from the sensors 14 into a standardized datapacket that can be interpreted and displayed by the main data collectionstation 130 at the remote monitoring system 18.

Referring now to the flow chart of FIG. 12, if an external device 38fails to generate a valid reading, as illustrated in step A, the controlunit 126 fills the portion of the patient data packet associated withthe external device 38 with a null indicator. The null indicator can bethe lack of any characters between commas in the patient data packet.The lack of characters in the patient data packet can indicate that thepatient was not available for the patient data recording. The nullindicator in the patient data packet can be interpreted by the main datacollection station 130 at the remote monitoring system 18 as a failedattempt to record the patient data due to the unavailability of thepatient, a malfunction in one or more of the sensors 14, or amalfunction in one of the external devices 38. The null indicatorreceived by the main data collection station 130 can indicate that thetransmission from the detecting system 12 to the remote monitoringsystem 18 was successful. In one embodiment, the integrity of the datapacket received by the main data collection station 130 can bedetermined using a cyclic redundancy code, CRC-16, check sum algorithm.The check sum algorithm can be applied to the data when the message canbe sent and then again to the received message.

After the patient data measurements are complete, the control unit 126displays the sensor data, including but not limited to blood pressurecuff data and the like, as illustrated by step B. In addition todisplaying this data, the patient data can be placed in the patient datapacket, as illustrated in step C.

As previously described, the system 10 can take additional measurementsutilizing one or more auxiliary or external devices 38 such as thosementioned previously. Since the patient data packet has a variablelength, the auxiliary device patient information can be added to thepatient data packet being compiled by the remote monitoring unit 22during patient data acquisition period being described. Data from theexternal devices 38 is transmitted by the wireless communication device16 to the remote monitoring system 18 and can be included in the patientdata packet.

If the remote monitoring system 18 can be set in either the auto mode orthe wireless only mode, the remote monitoring unit 22 can firstdetermine if there can be an internal communication error, asillustrated in step D.

A no communication error can be noted as illustrated in step E. If acommunication error is noted the control unit 126 can proceed towireless communication device 16 or to a conventional modem transmissionsequence, as will be described below. However, if the communicationdevice is working the control unit 126 can transmit the patient datainformation over the wireless network 16, as illustrated in step F.After the communication device has transmitted the data packet, thecontrol unit 126 determines whether the transmission was successful, asillustrated in step G. If the transmission has been unsuccessful onlyonce, the control unit 126 retries the transmission. However, if thecommunication device has failed twice, as illustrated in step H, thecontrol unit 126 proceeds to the conventional modem process if theremote monitoring unit 22 was configured in an auto mode.

When the control unit 126 is at the detecting system 12, and the controlunit 126 transmits the patient data over the wireless communicationdevice 16, as illustrated in step I, if the transmission has beensuccessful, the display of the remote monitoring unit 22 can display asuccessful message, as illustrated in step J. However, if the controlunit 126 determines in step K that the communication of patient data hasfailed, the control unit 126 repeats the transmission until the controlunit 126 either successfully completes the transmission or determinesthat the transmission has failed a selected number of times, asillustrated in step L. The control unit 126 can time out the and afailure message can be displayed, as illustrated in steps M and N. Oncethe transmission sequence has either failed or successfully transmittedthe data to the main data collection station, the control unit 126returns to a start program step 0.

As discussed previously, the patient data packets are first sent andstored in the wireless network storage unit 128. From there, the patientdata packets are downloaded into the main data collection station 130.The main data collection station 130 decodes the encoded patient datapackets and records the patient data in the patient database 140. Thepatient database 140 can be divided into individual storage locationsfor each patient such that the main data collection station 130 canstore and compile patient data information from a plurality ofindividual patients.

A report on the patient's status can be accessed by a medical providerthrough a medical provider workstation that is coupled to the remotemonitoring system 18. Unauthorized access to the patient database can beprevented by individual medical provider usernames and passwords toprovide additional security for the patient's recorded patient data.

The main data collection station 130 and the series of work stations 148allow the remote monitoring system 18 to monitor the daily patient datameasurements taken by a plurality of patients reporting patient data tothe single main data collection station 130. The main data collectionstation 130 can be configured to display multiple patients on thedisplay of the workstations 148. The internal programming for the maindata collection station 130 can operate such that the patients areplaced in a sequential top-to-bottom order based upon whether or not thepatient can be generating an alarm signal for one of the patient databeing monitored. For example, if one of the patients monitored bymonitoring system 130 has a blood pressure exceeding a predeterminedmaximum amount, this patient can be moved toward the top of the list ofpatients and the patient's name and/or patient data can be highlightedsuch that the medical personnel can quickly identify those patients whomay be in need of medical assistance. By way of illustration, andwithout limitation, the following paragraphs is a representative orderranking method for determining the order which the monitored patientsare displayed:

Alarm Display Order Patient Status Patients are then sorted 1 MedicalAlarm Most alarms violated to least alarms violated, then oldest tonewest 2 Missing Data Alarm Oldest to newest 3 Late Oldest to newest 4Reviewed Medical Alarms Oldest to newest 5 Reviewed Missing Data Oldestto newest Alarms 6 Reviewed Null Oldest to newest 7 NDR Oldest to newest8 Reviewed NDR Oldest to newest.

Alarm Display Order Patient Status Patients can then sorted 1 MedicalAlarm Most alarms violated to least alarms violated, then oldest tonewest 2 Missing Data Alarm Oldest to newest 3 Late Oldest to newest 4Reviewed Medical Alarms Oldest to newest 5 Reviewed Missing Data Oldestto newest Alarms 6 Reviewed Null Oldest to newest 7 NDR Oldest to newest8 Reviewed NDR Oldest to newest.

As listed in the above, the order of patients listed on the display canbe ranked based upon the seriousness and number of alarms that areregistered based upon the latest patient data information. For example,if the blood pressure of a single patient exceeds the tolerance leveland the patient's heart rate also exceeds the maximum level, thispatient will be placed above a patient who only has one alarm condition.In this manner, the medical provider can quickly determine which patientmost urgently needs medical attention by simply identifying thepatient's name at the top of the patient list. The order which thepatients are displayed can be configurable by the remote monitoringsystem 18 depending on various preferences.

As discussed previously, the escalation server 150 automaticallygenerates a notification message to a specified medical provider forunacknowledged data packets based on user specified parameters.

In addition to displaying the current patient data for the numerouspatients being monitored, the software of the main data collectionstation 130 allows the medical provider to trend the patient data over anumber of prior measurements in order to monitor the progress of aparticular patient. In addition, the software allows the medicalprovider to determine whether or not a patient has been successful inrecording their patient data as well as monitor the questions beingasked by the remote monitoring unit 22.

As previously mentioned, the system 10 uses an intelligent combinationof sensors to enhance detection and prediction capabilities.Electrocardiogram circuitry can be coupled to the sensors 14, orelectrodes, to measure an electrocardiogram signal of the patient. Anaccelerometer can be mechanically coupled, for example adhered oraffixed, to the sensors 14, adherent patch and the like, to generate anaccelerometer signal in response to at least one of an activity or aposition of the patient. The accelerometer signals improve patientdiagnosis, and can be especially useful when used with other signals,such as electrocardiogram signals and impedance signals, including butnot limited to, hydration respiration, and the like. Mechanicallycoupling the accelerometer to the sensors 14, electrodes, for measuringimpedance, hydration and the like can improve the quality and/orusefulness of the impedance and/or electrocardiogram signals. By way ofillustration, and without limitation, mechanical coupling of theaccelerometer to the sensors 14, electrodes, and to the skin of thepatient can improve the reliability, quality and/or accuracy of theaccelerometer measurements, as the sensor 14, electrode, signals canindicate the quality of mechanical coupling of the patch to the patientso as to indicate that the device is connected to the patient and thatthe accelerometer signals are valid. Other examples of sensorinteraction include but are not limited to, (i) orthopnea measurementwhere the breathing rate is correlated with posture during sleep, anddetection of orthopnea, (ii) a blended activity sensor using therespiratory rate to exclude high activity levels caused by vibration(e.g. driving on a bumpy road) rather than exercise or extreme physicalactivity, (iii) sharing common power, logic and memory for sensors,electrodes, and the like.

While the exemplary embodiments have been described in some detail, byway of example and for clarity of understanding, those of skill in theart will recognize that a variety of modifications, adaptations, andchanges may be employed. Hence, the scope of the present inventionshould be limited solely by the appended claims.

What is claimed is:
 1. A respiratory monitoring system for monitoring apatient, comprising: a patient detecting system comprising, an adherentdevice configured to couple to a patient, the adherent device comprisinga plurality of sensors configured to monitor physiological parameters ofthe patient to determine respiratory status, at least one of theplurality of sensors configured to monitor the patient's respiration,electronic circuitry coupled to the plurality of sensors, the electroniccircuitry comprising a wireless communication device, and a flexible,breathable cover disposed over the electronic circuitry; and a remotemonitoring system coupled to the wireless communication device, thewireless communication device configured to transfer patient data fromthe plurality of sensors to the remote monitoring system.
 2. The systemof claim 1, wherein the plurality of sensors are configured to monitorrespiration of the patient with a bioimpedance sensor.
 3. The system ofclaim 1, wherein the plurality of sensors comprises a combination ofsensors and the combination of sensors comprises as least one of abioimpedance sensor, a heart rate sensor or a pulse oximeter sensor. 4.The system of claim 1, wherein the wireless communication device isconfigured to receive instructional data from the remote monitoringsystem.
 5. The system of claim 1, further comprising: a processorcoupled to the plurality of sensors and to the wireless communicationdevice, the processor configured to receive data from the plurality ofsensors and process the patient data to generate processed patient data.6. The system of claim 5, wherein the processor is located at the remotemonitoring system.
 7. The system of claim 5, the patient detectingsystem comprises a monitoring unit.
 8. The system of claim 1, whereinthe remote monitoring system comprises logic resources located at theremote monitoring system, the logic resources configured to determine aphysiological event of the patient and determine the respiratory statusof the patient.
 9. The system of claim 7, wherein the monitoring unitcomprises logic resources configured to determine the respiratory statusof the patient and to determine a physiological event of a patient, thephysiological event comprising apnea.
 10. The system of claim 1, whereinthe plurality of sensors are configured to monitor respiration of thepatient with at least one of heart rate or pulse oximetry monitoring.11. The system of claim 1, wherein the plurality of sensors areconfigured to monitor respiration of the patient with a bioimpedancesensor and at least one of heart rate monitoring or pulse oximetrymonitoring.
 12. The system of claim 1, wherein the adherent device isconfigured to monitor the patient's respiration continuously.
 13. Thesystem of claim 1, wherein the adherent device is configured to monitora pulmonary disorder comprising at least one of chronic obstructivepulmonary disease, asthma or sleep disordered breathing.
 14. The systemof claim 1, wherein the plurality of sensors comprises a posture sensorfor orthopnea monitoring.
 15. The system of claim 14, wherein theposture sensor comprises at least one of a piezoelectric accelerometer,capacitive accelerometer or electromechanical accelerometer.
 16. Thesystem of claim 14, wherein the posture sensor comprises a 3-axisaccelerometer.
 17. The system of claim 1, wherein the patient detectingsystem and the remote monitoring system are configured to monitor thepatient for a patient sleep study.
 18. The system of claim 17, whereinthe plurality of sensors comprises a patient movement sensor.
 19. Thesystem of claim 18, wherein the patient movement sensor comprises atleast one of a piezoelectric accelerometer, a capacitive accelerometeror an electromechanical accelerometer.
 20. The system of claim 18,wherein the adherent device comprises a plurality of patches, wherein atleast a first patch of the plurality is configured for placement athorax of the patient, and at least a second patch of the plurality isconfigured for placement at another patient site away from the thorax tomeasure patient movement.
 21. The system of claim 1, further comprisinga processor configured to determine the respiratory status in responseto a weighted combination of change in sensor outputs.
 22. The system ofclaim 1, further comprising a processor configured to: detect when afirst rate of change of at least two sensor outputs measured over afirst period of time is greater than a second rate of change in thesensor outputs measured over a second period of time that is longer thanthe first period of time; and upon such detection, determine therespiratory status of the patient.
 23. The system of claim 22 whereinthe first period of time comprises no more than about 10 seconds and thesecond period of time comprises at least about one hour.
 24. The systemof claim 1, further comprising a processor configured to determine therespiratory status of the patient in response to a tiered combination ofat least a first sensor output and a second sensor output, with thefirst sensor output indicating a problem that is then verified by atleast a second sensor output.
 25. The system of claim 1, furthercomprising a processor configured to determine a physiological event ofthe patient in response to a variance from baseline values of sensoroutputs.
 26. The system of claim 25, wherein the baseline values aredefined by a look up table.
 27. The system of claim 1, wherein theplurality of sensors comprises at least a first sensor, a second sensorand a third sensor.
 28. The system of claim 1, wherein the covercomprises an elastomer.
 29. The system of claim 28, wherein theelastomer is fenestrated.
 30. The system of claim 1, wherein the covercomprises a breathable fabric.